Multi-component computer systems often require that each component be operating at the same frequency. Even very small tolerances may be unacceptable. For example, the operating system in a multi-processor computer system may require that each processor be operating at the same frequency so that the operating system can expect processes to complete at the same time regardless of which processor is executing the process.
A single clock is typically implemented as a universal reference for all of the components in a multi-component computer system, and the clock signal is distributed to each of the components in the multi-component system. However, this architecture necessarily has a single point of failure (i.e., the single clock), which may result in a system-wide failure.